1. Field of the Invention
This invention relates to electrical connecting devices for terminating cords, and more particularly, to devices for making electrical connections between a cord comprising flexible conductors and terminals which includes strain-relief facilities for the cord which, surprisingly, are maintained effective during the application of retrograde forces to the cord during use by the customer.
2. Description of the Prior Art
In the telephone industry, increasing use is being made of modular plug type connectors on straight and retractile handset and line cords which are used between the base and a handset of a telephone and between the base and a wall terminal block. In the presently used plugs, a terminal is applied to each of a plurality of insulated conductors contained within a jacketed length of a retractile cordage. These terminals are mounted within a dielectric structure which is attached securely to the associated cordage. The dielectric portions of the plugs, which are mounted on both ends of a length of cordage, cooperate with receptacles in the handset and in the base of the telephone to properly align the terminals of the plug with mating terminals within the components of the telephone.
In one presently used plug disclosed in U.S. Pat. No. 3,699,498 issued on Oct. 17, 1972 in the names of E. C. Hardesty, C. L. Krumreich, A. E. Mulbarger, Jr. and S. W. Walden, conductors are confined in conductor-receiving troughs formed in a dielectric base by a cover bonded to the base. Flat terminals are then inserted into individual grooves in the base in a side-by-side arrangement with contact portions thereof extending into engagement with the conductors. When the plug is inserted into a jack of a telephone handset, portions of the terminals in the jack engage portions of associated terminals in the plug.
Provisions in the just-identified plug for contacting the external component may be changed to that described in U.S. Pat. No. 3,761,869 issued on Sept. 25, 1973 in the names of E. C. Hardesty, C. L. Krumreich, A. E. Mulbarger, Jr. and S. W. Walden. There, the external contact portions of the terminals of the plug consist of an edge exposed to the exterior of the dielectric enclosure,
There has been some thought given to the cost involved in insuring a reliable securing together of the parts of the plug shown in U.S. Pat. No. 3,699,498. It would be desirable both from the ease and the cost of manufacturing to construct a one-piece plug, into which a telephone cord end may be inserted and secured and subsequently engaged by terminals moved into terminal-receiving openings in the plug.